This invention relates to a connector connected to an electric cable and covered with a conductive housing or casing in order to avoid electromagnetic interference (EMI) with its surroundings.
In the manner which will later be described more in detail, a connector comprises an insulator body or block and a plurality of conductive contacts extended forwardly from the insulator body. Typically, the conductive contacts are firmly held by the insulator body and connected to conductive wires of a cable which extends backwardly from the insulator body.
When used to cover the insulator body and the conductive contacts, a conductive housing comprises a metal front shell having primarily a pair of parallel opposing portions to protect the conductive contacts and first and second back shells put in electric contact with each other and having primarily first and second inside surfaces in mechanical contact with the insulator body and in electric contact with the opposing portions. In a conventional connector of the type described, the electric contact between the opposing portions and the first and the second inside surfaces is often insufficient and unreliable.
The conductive contacts are usually brought into force fit into a plurality of holding holes formed through the insulator body to open at its front and back surfaces. More particularly, each conductive contact comprises a contact stem having a planar surface and for force fit in a corresponding one of the holding holes, a contact end extended from the contact stem for forward projection from the insulator body and curved relative to the planar surface, and a contact leg extended from the contact stem opposite to the contact stem for connection to a corresponding one of the conductive wires. In order to make it possible to force such a conductive contact into the insulator body from the back surface, a guide way is added to each holding hole to enable pass therethrough of the contact end. Such guide ways are left open at the back surface. The conductive housing is generally covered with a hood of an insulator material.
In a conventional connector of this type, the insulator material flows into the guide ways to deteriorate electric contact between the contact stems and the conductive wires. Potting has consequently been mandatory so as to prevent the insulator material from flowing into the guide ways. Potting is, however, troublesome, raises the cost of manufacture of such connectors, and gives rise to fluctuations in quality of the connectors.
A connector often comprises the conductive contacts of the type described in one-to-one correspondence to the conductive wires of a cable with each conductive contact made to comprise a bifurcated conductive end in place of the contact leg. More specifically, the bifurcated conductive end is extended perpendicularly of the planar surface of the contact stem. The conductive wires are brought into press fit in the bifurcated conductive ends of corresponding ones of the conductive contacts. In such an event, first and second cover components of an insulator cover are provided with a plurality of protrusions to hold the conductive wires in correspondence to the bifurcated conductive ends.
On assembling such a connector, the first and the second cover components are pressed against each other with the bifurcated conductive ends interposed. An appreciable length of each conductive wire is exposed to surroundings. When used, the conductive housing may be undesirably brought into electric contact with the conductive wires of such an appreciable length. It has therefore been practice to interpose an insulator sheet between the conductive wires and the conductive housing. This objectionably renders the connector thick.